1. Field of the Invention
The invention relates to a stator for a rotary electric machine and a rotary electric machine. More particularly, the invention relates to a stator and a rotary electric machine in which a joint portion where end portions of winding wire coils are joined is provided at a coil end.
2. Description of Related Art
The stator of a rotary electric machine has a construction in which winding wire coils are wound on a stator core. Portions where the wound winding wire coils are protruded in the axis direction of the stator core are termed coil ends. In many constructions, a plurality of winding wire coils are connected to each other at such a coil end.
For example, Japanese Patent Application Publication No. 2010-166803 (JP 2010-166803 A) shows how, at a coil end, end portions of winding wire coils are protruded in the axis direction of the stator.
In the case where end portions of winding wire coils are interconnected by joining at a coil end of a rotary electric machine stator, it is necessary to secure electrical insulation between the joint portions and a rotary electric machine case. To that end, for example, a resin coating is provided on the joint portions.
However, in the case where the joint portions are provided with a resin coating, there is possibility that the resin coating may fall away from the joint portions due to vibration or heating cycles, depending on the adhesion force of the resin coating. The fall-away of the coating from the joint portions due to heating cycles can possibly occur due to different thermal expansion coefficients of the conductor wires in the joint portions and the resin coating for electrical insulation which are obviously made of different materials.